“I was calling an Uber. It was quarter to midnight and I was on my phone.

“I was looking down towards Trafalgar Square and I was seeing where he was, how far away, and suddenly a hooded cyclist came by and stole my phone – just took it out of my hand.

“The terrifying thing is now, in London, there are so many stabbings, so many thefts. Apparently this happens all the time but it was such a violation.

“I shouted very loudly because I have a very loud voice. But it was quarter to midnight and no-one was around really. So he got away.”

The star said when he talked to insurers and phone company staff the next day, some asked “‘Is that the real Mr Biggins?’, so I said ‘Yes, it is’ which made it slightly better because I was so upset and angry.”

Asked whether thieves could access his celebrity contacts, Biggins, who is taking over the BBC station as guest editor for the day, said: “It’s a facial one, so they can’t get in, and I stopped it immediately I got home that night.”

Tony Blackburn (Kirsty O’Connor/PA)

Last year, DJ Tony Blackburn revealed that he had fought off muggers and was kicked in the head in a “horrible” ordeal in London.

The veteran broadcaster, 76, said the incident had occurred about three years previously.

“I was attacked by three people, knocked to the ground, kicked in the head,” he wrote on Twitter.

“Blood was everywhere and I fought back and they didn’t get my phone. It’s a horrible thing to happen.”

Good Morning Britain host Susanna Reid (Matt Crossick/PA)

He spoke after Good Morning Britain host Susanna Reid revealed that she chased a knife-wielding man who tried to mug her.

She “acted on instinct” and saw a “red mist” when she pursued the man who took her handbag some years ago.

“I got mugged once by a guy with a knife and my instinct was to run after him,” the 48-year-old said on the ITV show.

“It’s not rational and obviously it was dangerous. He got scared and dropped my bag.”

Reid said the incident had a “traumatic effect” on her and later tweeted that she would not suggest anyone does the same, saying: “Not sure it was brave. Was acting on instinct. Wouldn’t recommend.”

Biggins is one of four presenters who have been guest-editing BBC Wiltshire this week for the station’s 30th birthday.